I have a bunch. Brace yourselves.
1) Pop'n Music. Really fun music game with a bunch of good music and cool characters. (Although I refuse to graduate to using all 9 buttons...)
2) Beatmania IIDX. Also a fun music game, not as cutesy as Pop'n but great nonetheless. Plays a lot like osu!mania, if you're interested.
3) Trickster Online. While all the official servers are closed now (worldwide, unfortunately), private servers gave me the chance to rediscover this MMO. Anime graphics, characters wearing animal ears (when you first create them, they can be taken off later)...what's not to love?
4) Pangya. It may be golf, but it's golf that's actually fun, in my opinion. Another MMO with anime graphics, I recommend it even if you don't like golf.